Conventionally, a process cartridge is known in the art, which includes a drum cartridge and a development cartridge detachably attached to the drum cartridge. To be more specific, this type of process cartridge includes a lock lever swingably supported on the drum cartridge.
The lock lever contacts with a part of the development cartridge in a state in which the development cartridge is attached to the drum cartridge, so that the development cartridge is locked to the drum cartridge to prevent disengagement of the development cartridge from the drum cartridge. When the user rotates the lock lever to unlock, the lock lever is released from the locked position to unlock the development cartridge from the drum cartridge.
In the aforementioned process cartridge, the development cartridge is unlocked from the drum cartridge only during the time that the user retains the rotated lock lever in the unlocked position. However, once the user releases his hand from the lock lever, the development cartridge is again locked to the drum cartridge by the lock lever. For this reason, the user has to remove the development cartridge from the drum cartridge by one hand, while operating the lock lever by the other hand. This leads to poor operability of the process cartridge.